The present invention is directed to a prefabricated window system, and more particularly to a prefabricated slider window system having a main frame which mounts two windows for lateral sliding movement.
Prefabricated window systems are frequently used, both for new construction and for replacement purposes, in order to provide high quality at a moderate cost. The desirable attributes of a prefabricated window system are easier to state than to achieve. The window system should be relatively inexpensive both to purchase and to install, but it should nevertheless offer excellent security against the elements. Furthermore, the window system should be sufficiently rugged to withstand many years of hard use, without the window sashes sticking. The window system should also have an attractive appearance and it should be relatively easy to clean the window panes in order to maintain the attractive appearance.
A "double-hung" window system is perhaps the most familiar type of window system in residential construction. In a typical double-hung window system two sashes are mounted so that they are vertically moveable, with one sash being positioned above the other when the window system is in a closed condition. In a typical "slider" window system, on the other hand, there are two window sashes which are mounted for horizontal rather than vertical movement. When the slider window system is in its closed condition the window sashes are positioned side-by-side at the same height.
The S 771 (.TM.) prefabricated double-hung window system of Rehau Inc., having an office in Leesburg, Virginia, is described in pending application Ser. No. 06/929,303, filed Nov. 12th, 1986. This window system includes a rectangular main frame having top and bottom frame portions which are joined by side frame portions. To reduce manufacturing costs all of the frame portions, which are made of extruded vinyl, have substantially the same cross-sectional configuration. The frame portions provide channels which, on the side frame portions, serve to guide two window sashes and a screen member so that they can be raised or lowered. Each sash carries a glazing unit having two spaced-apart window panes. To facilitate cleaning of the outdoor-side of the glazing units, the bottom ends of the sashes are pivotably connected to attachment members which slide in channels in the side frame portions. At the tops of the sashes are mounted releasable latch mechanisms which normally extend into the channels of the side frame portions. However, these latch mechanisms can be withdrawn to permit the upper ends of the sashes to be pivoted away from the main frame and toward the interior of the building. This permits a person in the interior of the building to clean the outdoor-side of the glazing units.
This technique for gaining access to the outdoor-sides of the glazing units cannot be directly transferred to a slider window system, since the slider sashes are guided by channels in the top and bottom frame portions rather than the side frame portions. One result of this difference, for example, is that the slider sashes are not pivotably supported by attachment elements which slide in channels in the side frame portions. Nevertheless, one might attempt to adapt the technique to a slider window system by pivotably attaching one end of each slider sash to attachment elements which slide in channels of the top and bottom frame portions. Latch mechanisms for engaging the top and bottom frame portions might then be placed at the other ends of the slider sashes to permit the sashes to be pivoted toward the interior of the buildings somewhat like pages of a book. In effect, a double-hung window system would be rotated by 90.degree. to transform it into a slider window system. This, however, would require the presence of various elements which would not otherwise be needed in a slider window system. Furthermore, the downward force on a sash when it is pivoted out of the slider main frame might push the attachment members in opposite directions, causing the sash to become mis-aligned with the main frame and perhaps permitting the sash to crash unexpectedly to the floor.